FABRICATION AND CHARACTERIZATION OF MULTIFUNCTIONAL POLYETHERIMIDE/CARBON NANOFILLER COMPOSITES
Polyetherimide (PEI) is a high-performance thermoplastic, showing great potential in many important applications including airplanes and electronics, due to its excellent mechanical and thermal properties. At the same time, with the rapid development of nanotechnology, adding various nanomaterials to polymeric materials to fabricate polymer nanocomposites has become a popular and efficient way to develop advanced materials. Graphitic carbon nanofillers (GCNs), benefiting from their unique SP2 hybridized carbon structure, exhibit superior mechanical, thermal and electronic properties, and prove to be an all-purpose nanomaterials for next-generation polymer nanocomposites. This project focuses on development of new generation PEI/GCN nanocomposites with substantially improved mechanical properties, static dissipation and acoustic damping; as well as functionalities to satisfy a variety of applications including airplanes, ground transportation and electronics. In order to achieve these goals, efforts have been made to control dispersion as well as surface modification of GCNs in PEI matrix. Dispersion of GCNs is a critical factor for properties of polymer nanocomposites, impacting both fundamental mechanical properties and physical properties. At the same time, proper surface modification can improve dispersion of GCNs, strengthen interfacial bonding between PEI and GCNs, and impart new functionalties to the resultant nanocomposites. The results showed success in comprehensively improving properties and functionalities of PEI/GCN nanocomposites. Effective control of GCN dispersion and efficient surface modification has substantially improved mechanical, thermal, tribological, damping, and static dissipation properties of PEI/GCN nanocomposites. The structure-property relationships of PEI nanocomposites have also been discussed in detail for further materials design and optimization of material properties. Based on these relationships, a novel non-destructive evaluation method has been developed to quantitatively examine the dispersion of GCNs in polymer nanocomposites. This research may substantially expand potential applications of PEI and its nanocomposites.